Solar cell



FIG. 1 is a front perspective view of a solar cell showing the claimed design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top plan view thereof, the bottom plan view being a mirror image thereof; and,

FIG. 5 is a right side view thereof, the left side view being a mirror image thereof.

In the drawings, the broken lines show portions of the solar cell that form no part of the claimed design. 

CLAIM The ornamental design for a solar cell, as shown and described. 